The present invention relates to a recording/reproduction or a reproduction or a recording apparatus for recording and/or reproducing images and audio data or controlling the reproduction or recording, or more in particular to a recording/reproduction or a recording or a reproduction apparatus for controlling the recording/reproduction or reproduction or recording of a recording medium by duplication management information.
The DVD-ROM is a recording medium having a capacity about seven times as large as the CD-ROM. The DVD-ROM can record even movie software as well as the program code for personal computers (PC) by compressing video and audio data. The recording media for recording data on DVD include DVD-RAM, DVD-R and DVD-RW. A large amount of data can be recorded in these media, and therefore it is necessary to prevent the illegal digital duplication of the movie software or the like as such. Therefore, the technique for preventing the illegal duplication plays an important role for this purpose.
Such techniques include an electronic watermark, the standardization of which is described in xe2x80x9cNikkei Electronicsxe2x80x9d, pp.31-32, May 18, 1998, published by Nikkei BP Co., Ltd.
Apart from the electronic watermark technique, the technique for preventing the illegal duplication in data exchange between equipment using IEEE1394 is also described in the Mar. 23, 1998 issue of xe2x80x9cNikkei Electronicsxe2x80x9d, pp.47-53, published by Nikkei BP.
With the devices such as the DVD-RAM drive which includes digital/analog input/output means, however, it is difficult to prevent illegal duplication with these techniques alone. Such techniques are even sometimes easily avoided. Also, data exchange within the personal computer is more complicated, often generating a loophole of duplication control.
In view of this, it is necessary to configure a system using an appropriate combination of a plurality of duplication control techniques including the watermark technique and the IEEE1394 antiduplication technique
In order to achieve the object mentioned above, according to a first aspect of the present invention, there is provided a data recording apparatus comprising means for compressing an image signal, first conversion means for converting the compressed data into a format for recording in a recording medium, and means for recording the data in the recording medium,
wherein the compression means includes first detection means for detecting the added information embedded in the image signal.
According to a second aspect of the invention, there is provided a data reproduction apparatus comprising means for reproducing data from a recording medium, second conversion means for converting the reproduced data from the format recorded in the recording medium to the format for demodulating the image signal, and means for expanding the data converted in the second conversion means in accordance with a method by which the data are compressed;
wherein the expansion means includes second detection means for detecting the added information embedded in the image signal.
According to a third aspect of the invention, there is provided a data recording/reproduction apparatus, wherein the expansion means includes rewrite means for rewriting the added information, and the reproduction means includes third detection means for detecting a signal for determining whether the recording means recorded in the recording medium is a formal one or not, each means of the apparatus including authentication means for mutual authentication among the means.
According to a fourth aspect of the invention, there is provided a baseband recording/reproduction apparatus and a bit stream recording/reproduction apparatus in which a MPEG encoder/decoder, a bit stream encoder/decoder, recording means and reproduction means each have an appropriate duplication control means thereby to prevent the copyrighted data from being illegally recorded or reproduced.
According to a fifth aspect of the invention, there is provided a similar recording/reproduction apparatus comprising a MPEG encoder/decoder including watermark detection means and renew means for detecting and updating the watermark from the baseband data.
According to a sixth aspect of the invention, there is provided a similar apparatus, wherein the recording means or the reproduction means includes watermark detection means and watermark renewing means, whereby the watermark in the signal recorded in the disk or reproduced from the disk can be detected and renewed, thereby making it more difficult to avoid the detection and updating than with the MPEG encoder/decoder.
Further, even in the case where the recording medium is replaced with another type, the method for detecting/updating the watermark remains the same.